<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

     div{
        width: 60px;
        height: 60px;
        border:1px red solid;
        background-color: black;
        text-align: center;
        line-height: 60px;
        color: #fff;
        font-size: 30px;
        margin: 100px auto;
        border-radius: 5px;


     }

    </style>
</head>
<body>
    

       <div>3</div>
</body>
</html>